Chair



M. KRAUSE April 28, 1931.

CHAIR Original Filed March 12. 1929 gnu u. I m

tion and partly Patented Apr. 28, 1931 sates MAX KRAUSE, OF CHICAGO,ILLINOIS CHAIR Application filed March 12, 1929, Serial No. 346,417.Renewed September 16, 1930.

My invention relates to chairs, and its main object is to provide newand improved interengaging means between the chair-frame and theadjustable back-member which in different positions of the latter on theframe are automatically interlocked by the weight of the user and areautomatically unlocked when the chair is unoccupied.

The invention consists in certain organizations and arrangements ofparts of which practical embodiments are shown in the accompanyingdrawing, in which Fig. 1 is a view partly in sectional elevain sideelevation of a chair made in accordance with my invention, the viewbeing taken in part on the line 11 in Fig. 3 and showing the seat in itsinner position in the frame.

Fig. 2 is a similar view on the same line with the seat in its extendedposition;

Fig. 3 is a view partly in section and partly in rear elevation on theline 3-3 in Fig. 1, with parts broken away;

Fig. 4c is a detail sectional view showing the means for automaticallyengaging and disenaging the back-frame and chair-frame, and

Fig. 5 is a detail sectional view on the line 5-5 in Fig. i. j

In the drawings the reference numeral indicates generally therectangular base of a chair-frame having usual feet, front and rearcorner uprights 11 and 12, respectively, connected by side-arms 13. Thebase 10 has opposite longitudinal tracks 14 upon which the seat-frame 15is supported by pairs of roller-bearings 16 and 17 respectively securedat each side of the front end of the base 10 and at each side of therear end of the seatframe so that the latter moves easily back and forthon the tracks, and the tracks are provided with one or more pairs ofopposite seats 18 in which the rollers 17 rest in different adjustedpositions of the seatframe, and with rear stops 19 against which thatframe abuts when its rollers 17 enter the rear seats 18 as shown inFig. 1. The tracks 14 support opposite inwardly directed guiderails 20upon which travels a cross-piece 21 secured on the rear end of theseat-frame and having grooves or hannels 22 in its ends to slidablyengage the rails 20 and guide the seat-frame in its reciprocatingmovements and hold it against upward displacement and tipping, therebeing suficient play between these parts to permit the rollers 17 toengage and disengage their seats. The back-frame 23 is hinged at itslower end to the rear end of the seat-frame 15, and carries above itscenter rigid lateral projections, preferably formed by the projectingends of a cross-rod 24: fixed in the back-frame, and the upper portionsof the rear uprights 12 are formed with inwardly and downwardly curvedthroughslots or guideways 25 in which the projections travel when theseat and back-frames are shifted. The guideways 25' are provided intheir rear or outer walls with a plurality of inwardly opening seats 26arranged in opposite pairs into which the ends of the rod can enter tohold the back-frame inany of its adjusted positions; the seats 26correspond innumber and arrangement with the seats 18, so that when therollers 1'? rest in their rear seats the rod aligns with its upper seats26 as shown inFig. 1, and when the rollers 17 rest in their front seatsthe rod aligns with its lowest seats as shown in Fig. 2, andcorrespondingly for intermediate positions of the seat frame. The upperends of the uprights 12 are divided intosections alongthe line of theslots 25; the sections are held in position by suitable means, such 27,and the opposite walls of their slots are formed-with alined mortises 28and 29 to form enclosed ways for metallic yokes or stirrups 30 havingloops of substantially the con tour of the slots and through which theends of the rod 24f pass. The yokes are free to move transversely of theslot-s 25 and are spring-stressed to hold the rod out of engagement withits seats 26 when the chair is unoccupied as shown in Figs; 1 and 2, sothat the back 23 can be easily and freely shifted with the seat 15, andto yield under increased pressure, as for example the weight of a personoccupying the chair, to permit the rod to engage a pair'of its seats asshown for example in Fig. & and lock the back and seat sectionsin'positionon the frame. The spring support for the yokes may beprovided in any suitable as the dowels manner, and in theexemplification shown each yoke is suspended in its housing by aretractile coil-spring 31 connected at one end to an eye 82 on the yokeand at its other end to a pin 33 in a recess in the upright; the onlyessential feature of the spring-support is that it be strong enough tonormally overcome the weight or pressure ofthe chair-back itself, sothat the rod will not engage its seats when the chair is unoccupied andwill ride on the loop past its seats when the seat-section is movedoutwardly or inwardly on the base.

WVhen the parts are positioned as shown in Fig. 1, the rod 2& is alignedwith the upper pair of seats 26, but is held out of engagement therewithby the spring-stressed yokes, and when the seat is moved outwardly intoan extended position, as for example in Fig. 2, the rod rides along theyokes past its seats and does not enter or engage them; and the sameaction occurs when the seat is moved inwardly. When the connected seatand back are adjusted to any position in which the rod aligns with apair of its seats 26 increased weight or pressure on the back, as by anoccupant of the chair, overcomes the resistance of the springs andinterlocks the rod with the seats as shown in Fig. 4: for example, andthe back and seat are held in position; the engagement of the rollers 17and their seats 18 supplements the interengagement of the other totravel on said tracks, a back-section hinged to the inner end of saidseat-section, a crossrod fixed on the back-section and movable in saidslots and adapted to enter said seats, the walls of said slots havingopposite mortises to form ways, yokes corresponding in contour to saidslots and movable transversely thereof in said ways and engaging saidrod, and springs normally supporting said yokes in position to hold saidrods outside its seats.

In testimony whereof I affix my signature.

MAX KRAUSE.

parts for this purpose. When the chair is vacated the springs 31 restorethe parts to their position shown in Figs. 1 and 2, and the back-frameis free to be easily moved with the seat-frame into another position.The rollers 17 engaging their seats 18 hold the seat and back in placewhen the chair is unoccupied.

I claim:

1. In a chair, the combination with a frame having opposite tracks andcurved guides above the tracks provided with seats, of a seat-sectionpositioned to travel on said tracks, a back-section hinged to the innerend of said seat-section, lateral projections on the back-sectionmovable in said guides, and spring-actuated yokes mounted in the frameand normally holding the projections out of engagement with said seats.

2. In a chair, the combination with a frame having opposite tracks andinwardly curved guides located above the tracks and provided with seats,of a seat-section positioned to travel on said tracks, a back-sectionhinged to the inner end of the seat-section, a crossrod fixed on theback-section and movable in said guides and adapted to enter said seats,and spring-actuated yokes mounted in the frame and normally holding saidrod out of engagement with said seats.

3. In a chair, the combination with a frame having opposite tracks andinwardly curved slots above the tracks and seats in the outer walls ofthe slots, of a seat-secti0n positioned

